I agree that the uber-frugal comments can drive some people away and there is the risk of throwing out the baby with the bathwater. Personally we are not very frugal at all compared to the standards around here, though we outwardly appear to spend much less than most other people around us. I cut my husband's hair, we do most cooking at home, have old, used furniture, and buy my kid's clothes second-hand. On the other hands, we spend more in rent than many people here spend in a month and our rent plus childcare is probably more than many people take home in a year. We also have the luxury of spending freely at the grocery store, buying new socks whenever the old ones have holes, go on vacation to Hawaii if we feel like it because we are blessed with high incomes. That doesn't stop us from practicing the fundamentals of mustachianism: be thoughtful about our purchases, identify what truly brings us joy and spend money freely there, all while saving a significant portion of our income.
The benefit I do see to everyone chiming in about how they only own one 20 year-old used couch is that it helps to counterbalance all of the commercials and other messages that are sent out all the time about how it is normal to spend-spend-spend. Not only is it okay to have cheap furniture and a small-ish house, it is normal around here. Humans are very social so it is hard to buck the trends of those around you. THat is the very reason we find each other online here so we can all pat each other on the back and normalize what feels very abnormal in the "real" world.